sim_ttest = function(n = 200, GR = 1, SDR = 1, M_diff = 0) {
n1 = round(n / (GR + 1))
n2 = round(n1 * GR)
sd1 = 1
sd2 = sd1 * SDR # sd2/sd1
g1 = rnorm(n = n1, mean = 0, sd = sd1) # control
g2 = rnorm(n = n2, mean = M_diff, sd = sd2) # treatment
welch = t.test(g1, g2)$p.value
student = t.test(g1, g2, var.equal = TRUE)$p.value
res = list("Welch" = welch, "Student" = student)
res
}
sim_ttest(n = 100, M_diff = 0.3)$Welch
[1] 0.2752475
$Student
[1] 0.2752067